In the modern world, the functional food market is expanding with the increase in complex metabolic syndromes caused by obesity (based on the year 2014, 18% of OECD adults) and diabetes (based on the year 2011, 6.9%).
The metabolic syndrome refers to the complex occurrence of obesity, type 2 diabetes caused by insulin resistance, and various metabolic abnormalities. The metabolic syndromes rapidly increase due to the aging population and high-calorie diets habits, causing social costs, and thus the prevention of fundamental causes and the development of medical or food materials are urgent.
In the human intestinal ecosystem, microbes are present at birth to maintain the balance between beneficial bacteria and harmful bacteria. The microbes form intestinal microflora, coexist with humans, and have a direct or indirect effect on human health through interactions with humans. Recently, the National Institutes of Health (NIH) researched the relationships between intestinal microflora and diseases through the “Human Microbiome Project”, and raised the importance of the normalization of the intestinal flora since having unbalanced microbial flora causes the occurrence of inflammatory enteric diseases and the like.1,2 
According to the paper about the association between obesity and gut microbiome, which was published on the scientific journal “Nature” in 2006, slim people are different from obese people with respect to gut microbiome distribution, and it was confirmed through an experiment using mice that bacteria belonging to the Firmicutes show a relatively higher component percentage than bacteria belonging to the Bacteroidetes in obese mice.3 Since then, the research about intestinal microbes and the human body has been conducted in various fields, and the development of intestinal microflora improving preparations is needed for the suppression of obesity and the treatment of diseases through the improvement in intestinal microflora.
Approximately 500,000 species of marine organisms, which correspond to about 80% of all species on Earth, are assumed to exist. However, of these, less than 1% of the marine organisms are being developed as useful living resources, and thus have a very high development potential. Alginic acid, which is a representative seaweed polysaccharide as a seaweed-derived functional material, is contained in 15-35% of brown algae, such as kelp or seaweed, and has polyuronide characteristics, in which two kinds of uronic acids, β-D-mannuronic acid (M) and α-L-guluronic acid (G), are connected via 1,4-glycosidic linkages at various ratios. Alginic acid-derived oligosaccharides may be classified into mannuro-oligosaccharide (MOS), guluro-oligosaccharide (GOS), and mannuronate and guluronate mixed oligosaccharide (alginate oligosaccharide, AOS), according to the component sugar, and may also be classified according to the double bond at the end of sugar.
Marine-derived polysaccharides have been used in human life for a long time, and the research about biological activities, such as anticancer activity, antioxidation, antihypertension, and antibiotic materials, which are derived from marine organisms, are being conducted actively and globally. The output of alginic acid sources produced globally is approximately 100,000 tons, of which about 30% are used as a food additive, but when the alginic acid sources are developed as high value-added medicinal sources, the values thereof can be doubled. The research of alginic acid-derived oligosaccharides achieves tangible results, such as being reported to have the biological activities of promoting the growth of roots of higher plants, promoting the growth of Bifidobacterium sp., anti-inflammation, antioxidation, and antibiotic activity, according to the structural feature, and thus alginic acid-derived oligosaccharides have widespread application fields.
Throughout the entire specification, many papers and patent documents are referenced and their citations are represented. The disclosure of the cited papers and patent documents are entirely incorporated by reference into the present specification and the level of the technical field within which the present invention falls, and the details of the present invention are explained more clearly.